2012 International Conference on Power, Signals, Controls and Computation最新文献

{"title":"Control strategy for a single phase bidirectional converter based UPS system using FPGA","authors":"B. I. Rani, G. S. Ilango, C. Nagamani, P. Rao","doi":"10.1109/EPSCICON.2012.6175245","DOIUrl":"https://doi.org/10.1109/EPSCICON.2012.6175245","url":null,"abstract":"Uninterruptible power supplies are widely used to supply uninterrupted power to the loads under power failure. Typical UPS systems consists of two power converters namely a rectifier/charger which charges the batteries and an inverter to provide an ac sinusoidal output. Employing a single converter for both rectification and inversion process reduces the hardware components. This paper presents a control strategy for the single phase bidirectional converter used in UPS systems. Under normal mode, the grid supplies the loads and charges the battery through the bidirectional converter. The converter is controlled using a hysteresis current controller and a constant current charging technique is used to charge the batteries. Upon grid failure, the battery supplies the load through the converter which operates in voltage control mode to maintain the load voltage. This system offers the advantage of reduced hardware, low harmonic distortion of line current and regulation of load voltage under grid failure. The control strategy is simulated in MATLAB/Simulink and implemented in an ALTERA cyclone II FPGA board. The steady state and the dynamic response of the system are simulated and verified experimentally on the prototype unit built in the laboratory.","PeriodicalId":143947,"journal":{"name":"2012 International Conference on Power, Signals, Controls and Computation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133336915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A study on the DC conductivity and thermoelectric properties of carbon nanotubes based Polyaniline composites","authors":"A. Sobha, S. Narayanankutty","doi":"10.1109/EPSCICON.2012.6175230","DOIUrl":"https://doi.org/10.1109/EPSCICON.2012.6175230","url":null,"abstract":"A series of nano composites containing multi-walled carbon nano tubes (CNT) and Polyaniline (PANI) has been prepared by in situ polymerisation process using Ammonium persulphate(APS) as oxidant and HCl as the dopant and by static interfacial method. Both neat and functionalised CNTs were used for preparing the composites. The morphology was studied using SEM. The composite powder was pressed into pellets and the DC conductivity, thermal conductivity and Seebeck coefficient were measured. The results showed that the nanocomposites had a core shell structure. The structure and uniformity of PANI coating over CNT core depended on functionalisation of CNTs and type of polymerisation process. Electrical and thermo electrical studies showed simultaneous increase in these properties for composites prepared by interfacial polymerisation and using functionalised nano tubes.","PeriodicalId":143947,"journal":{"name":"2012 International Conference on Power, Signals, Controls and Computation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114586187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fault identification in HVDC using artificial intelligence — Recent trends and perspective","authors":"M. Ramesh, A. Laxmi","doi":"10.1109/EPSCICON.2012.6175256","DOIUrl":"https://doi.org/10.1109/EPSCICON.2012.6175256","url":null,"abstract":"The safe operation of AC-DC systems requires the Monitoring of appropriate system signals, the accuracy and rapid classification of any perturbations so that protective control decisions can be made. In case of fast acting HVDC transmission system, such decisions must often be made within tens of milliseconds to guarantee safe operation from disturbances such as the common commutation failures. The detection and fast clearance of faults are important for safe and optimal operation of power systems. Due to the integration of fast acting HVDC systems in ac power systems, it is necessary to detect, classify and clear the faults as fast as possible. The source and cause of disturbances or faults must be known before appropriate mitigation action be taken. For secure operation of a system, a feasible approach is to monitor the signals so that accurate and rapid classification of fault is possible for making correct protective control decisions. However, fast and reliable fault identification is still a big challenge. It is not easy to identify HVDC faults by using pure frequency or pure time domain based methods. The pure frequency domain based methods are not suitable for the time-varying transients and the pure time domain based methods are very easily influenced by noise. Recently, due to advancement of power electronics technology, High Voltage Direct Current (HVDC) transmission technology has been utilized to identify the faults in power system. The HVDC Transmission system is very reliable, flexible and cost effective. Advances in artificial intelligence techniques such as Fuzzy, Neural and ANN etc. and Power Semiconductor devices have made tremendous impact in the identifying of faults in HVDC system. A case is made to present overview of the artificial intelligence techniques to identify the faults in HVDC transmission system.","PeriodicalId":143947,"journal":{"name":"2012 International Conference on Power, Signals, Controls and Computation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133887029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fuzzy logic based indirect vector control of induction generator in Wind Energy Conversion System","authors":"Y. S. Rao, A. Laxmi","doi":"10.1109/EPSCICON.2012.6175259","DOIUrl":"https://doi.org/10.1109/EPSCICON.2012.6175259","url":null,"abstract":"In order to meet increasing power demand, taking into account economical and environmental factors, wind energy conversion is gradually gaining interest as a suitable source of renewable energy. The modeling of Wind Energy Conversion System(WECS) is done in MATLAB-SIMULINK. The dynamic d-q model of the induction generator is developed from the fundamentals in a modular approach in simulink. A fuzzy logic controller is designed for indirect vector control of induction generator. The vector control or field oriented control of induction motor and synchronous motors brought a renaissance in the high performance control of ac drives. In the vector control, the induction motor can be controlled like a separately excited dc motor. In a separately excited dc motor, because of decoupling, when the field current If is controlled, it affects the field flux only but not the armature flux. Thus giving fast transient response in the dc drive. Because of the inherent coupling problem, an induction motor cannot give such a fast response. The dc machine like performance can also be extended to induction motor if the machine control is considered in the synchronously rotating reference frame (de-qe), where the sinusoidal variables appear as dc quantities in steady state. The speed control loop uses a fuzzy logic controller to produce a direct axis current reference Id* which controls the motor flux. The motor torque is controlled by quadrature axis current reference Id*. The correctness and effectiveness of the proposed fuzzy logic controller are verified by the simulation results.","PeriodicalId":143947,"journal":{"name":"2012 International Conference on Power, Signals, Controls and Computation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133002096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parameterized model order reduction for fast transient electromagnetic simulations","authors":"M. A. Bazaz, Mashuq-un-Nabi, S. Janardhanan","doi":"10.1109/EPSCICON.2012.6175271","DOIUrl":"https://doi.org/10.1109/EPSCICON.2012.6175271","url":null,"abstract":"Transient Electromagnetic problems constitute an area of significant investigative effort. The principal computational issue in these problems is the solution of large system of differential algebraic equations (DAE's) obtained after Finite Element (FE) discretization. Model Order Reduction (MOR) Techniques provide a mechanism to generate reduced order models from the detailed description of the original FE network. This is achieved by using moment matching techniques, where the reduced order model matches the moments of the original system to approximate the response with a low order transfer function. However, these numerical techniques all conserve the original system moments only with respect to frequency. While this provides a significant CPU cost advantage when performing a single frequency sweep, a new reduced order model is required each time a parameter is varied in the structure under study. This necessitates the use of parametric MOR strategies so as to expedite optimization and design space exploration cycles. In this work, we present a methodology for transient electromagnetic field simulations through parameterized model order reduction (pMOR). The proposed methodology is illustrated for a generic system with promising results and a significant saving in computational effort.","PeriodicalId":143947,"journal":{"name":"2012 International Conference on Power, Signals, Controls and Computation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124158378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Image denoising solutions using heat diffusion equation","authors":"K. Lakshmi, R. Parvathy, S. Soumya, K. P. Soman","doi":"10.1109/EPSCICON.2012.6175261","DOIUrl":"https://doi.org/10.1109/EPSCICON.2012.6175261","url":null,"abstract":"The idea of this paper is to model image denoising using an approach based on partial differential equations (PDE), which describes two dimensional heat diffusion. The two dimensional image function is taken to be the harmonic, when it can be obtained as the solution to the equation describing the the heat diffusion. To achieve this, image denoising is formulated as an optimization problem, in which a function with two terms is to be minimized. The first term is called the regularization term, which is some form of energy of the image (like Sobolev energy) and the second term is called the data fidelity term, which measures the similarity between the original image and the processed image. The two terms are combined using a control parameter whose value decides which term has to be minimized more. Image denoising problem could then be solved by a simple iterative equation, derived based on the Gradient Descent method.","PeriodicalId":143947,"journal":{"name":"2012 International Conference on Power, Signals, Controls and Computation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124500878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative evaluation of modelling methods for TCSC in optimal power flow studies","authors":"S. Sreejith, S. P. Simon, M. Selvan","doi":"10.1109/EPSCICON.2012.6175241","DOIUrl":"https://doi.org/10.1109/EPSCICON.2012.6175241","url":null,"abstract":"This paper presents a comparative evaluation of optimal power flow analysis incorporating Thyristor controller Series compensator using both variable reactance and firing angle model. In reactance model the TCSC is modeled as a variable reactance and in firing angle model nodal admittance matrix is firing angle dependent, which then incorporated into the existing optimal power flow algorithm. The reactance value of the TCSC is taken as the state variable in the former model and the firing angle is taken as the state variable in the later model. A comparative evaluation is carried out in terms of bus voltage, angle, power flow, active power loss and power generation cost for both variable reactance model and Firing Angle model which is validated on 5 bus test system and IEEE 30 bus test system using Newton's method.","PeriodicalId":143947,"journal":{"name":"2012 International Conference on Power, Signals, Controls and Computation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123263551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real time simulation: Recent progress & challenges","authors":"P. M. Menghal, A. Laxmi","doi":"10.1109/EPSCICON.2012.6175278","DOIUrl":"https://doi.org/10.1109/EPSCICON.2012.6175278","url":null,"abstract":"In order to compete in the global market, engineering organizations are under increasing pressure to design, develop, and deploy products in the market place as quickly as possible with first time quality. In order to achieve these objectives, it is necessary to streamline the design and development process, namely, “transfer of analytical design of Intelligence to Mechatronics intelligence” in an efficient and expedient manner. An increasing pressure exists on the development cycle of control systems to serve this widening application spectrum. The time-to-market of a new product often determines its commercial success. Consequently, design problems have to be discovered as early as possible in the design process in order to take remedial actions. Efficient and accurate tools and procedures are required to support short yet successful development processes. Over the last two decades, commercially available computer has become both increasingly powerful and increasingly affordable. This, in turn, has led to the emergence of highly sophisticated simulation software applications that not only enable high-fidelity simulation of dynamic systems and related controls, but also automatic code generation for implementation in industrial controllers. Simulation tools have been widely used for the design and improvement of electrical systems since the mid twentieth century. The evolution of simulation tools has progressed in step with the evolution of computing technologies. In last ten years, computing technologies have improved dramatically in performance and become widely available at a steadily decreasing cost. Consequently, simulation tools have also seen dramatic performance gains and steady cost decreases. Researchers and engineers now have access to affordable, high-performance simulation tools that were previously too cost prohibitive, except for the largest manufacturers and utilities. The purpose of this paper is to review major milestones that set the stage for the development of the today's real time simulation including sufficient detail to acquaint reader with their basic principles, strength, challenges and its applications.","PeriodicalId":143947,"journal":{"name":"2012 International Conference on Power, Signals, Controls and Computation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114011710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Power system stability enhancement with SMES","authors":"R. Khanna, G. Singh, T. K. Nagsarkar","doi":"10.1109/EPSCICON.2012.6175274","DOIUrl":"https://doi.org/10.1109/EPSCICON.2012.6175274","url":null,"abstract":"This paper presents improvement of transient stability of power systems with superconducting magnetic energy storage (SMES). SMES has been connected at the generator terminal for single machine connected to infinite bus (SMIB). A comparison of performance of proportional type of SMES (P-SMES) proportional-Integral type of SMES (PI-SMES)and that of an Optimally Switched Dynamic Brake (OSDB) suggested by Minisey et al is presented. Transient stability investigations were carried out on SMIB with SMES for diverse loading conditions and different fault clearing times. The results established superior performance of SMES in damping transient swings over optimally switched conventional dynamic brake.","PeriodicalId":143947,"journal":{"name":"2012 International Conference on Power, Signals, Controls and Computation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123540336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel neural network approach for digital image data encryption/decryption","authors":"S. Joshi, V. Udupi, D. R. Joshi","doi":"10.1109/EPSCICON.2012.6175229","DOIUrl":"https://doi.org/10.1109/EPSCICON.2012.6175229","url":null,"abstract":"With the increased popularity of multimedia applications, there is a great demand for secured data storage and transmission techniques. Information security has traditionally been ensured with data encryption and authentication techniques. Through the years, different generic data encryption standards have been developed. The secrecy of communication is maintained by secret key exchange. In effect the strength of the algorithm depends solely on the length of the key. The presented work aims at secure image transmission using randomness in encryption algorithm, thereby creating more confusion to obtain the original data. The security of the original cipher has been enhanced by addition of impurities to misguide the cryptanalyst. Since the encryption process is one way function, the artificial neural networks are best suited for this purpose as they possess features like high security, no distortion and its ability to perform for non linear input-output characteristics, In the presented work the need for key exchange is also eliminated, which is otherwise a perquisite for most of the algorithms used today. The proposed work finds its application in medical imaging systems, military image database communication and confidential video conferencing, and similar such application. The results are obtained through the use of MATLAB 7.0.1.","PeriodicalId":143947,"journal":{"name":"2012 International Conference on Power, Signals, Controls and Computation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122480745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}